Well, yes, I can nitpick, too - The sound itself is not euphoric - that would be the state I'd be in after hearing some euphonic (pleasant) sounds.
But nitpicking aside, how would you characterise this "perceived sound" before it was changed by the reflections? To me most box speakers sound, well, boxy.
That will teach me to keep posting from my phone.
Autocorrect is very annoying. I actually corrected it back at least once, and it still kept doing it. Humph.
The boxy thing is something I have thought about a lot over the years. I know a couple of dyed in the wool dipole enthusiasts, and the whole boxy sound comes up a lot. So, my personal take on it is that indeed, some boxes have enough internal resonant modes that are not well managed that they colour the sound. (I have read some clearly wrong attempts to explain that boxy modes can't affect the sound, even from some eminent sources.) Vented speakers have a worse time, partly because sound can exit the vent, but also because their nature requires a minimum of damping inside for the vented alignment to work at its best. Two way vented is the worst. However it need not be the case. Three way or more systems don't have frequencies in the main box that may be so affected, sealed alignments can be much more damped, and line systems (aka transmission lines - or quarter wave systems to be more correct) can have a long line of damping to kill off the resonances. They are also inherently highly braced. In my own speaker designs I have spent a lot of time experimenting with damping regimes and measuring the results, and I am convinced that for one - boxiness is very real, and that two - it need not be so.
Whether panel resonances can add to a boxy sound, or are just another nuisance, I don't know. It may depend upon what sonic colour you identify as "boxy", and given that that isn't well defined, it may be part of the problem in communicating the question in the first place. Again, my own speaker designs are silly dead. Constrained layer walls with constrained layer damping braces. Stupidly over engineered, heavy and not suitable for any sort of commercial design. Easy to do however. (And laminating the constrained layers a very messy business.)
In terms of justifying dipoles or panels, IMHO avoiding the "boxy" sound of boxes isn't a particularly good reason. Not all boxes need (or should) sound like a box. That some do isn't a reason to go without a box. The traditional speaker design has quite a few shortconings, and there are lots of attempts to address these flaws with other configurations or technologies, all with differing success, new flaws, and usually quite dubious price performance. There are quite a few reasons the vast majority of speakers are boxes.
The question of how a dipole operates in the room is however IMHO an interesting and open question. I keep citing Linkwitz, and I thing with good reason. He spent a lifetime researching the question, and his work was well respected by his peers. Including Olive. He held some specific ideas about the reasons why his speaker designs worked so well for him, ideas that there is probably some merit in forming the basis of proper research.
It is a pity the first dipole to be measured here is an entry level panel. I think the poor performance of this speaker is clouding the wider question of the value of people like Linkwitz's ideas. If someone could get an Orion or LX to Amir for measuring I think we could have a vastly more productive discussion.